Flange Gasket, Ring, 2 1/2 in Pipe Size, 4 7/8 in Outside Dia., Bolt Holes 0, 2 7/8 in Inside Dia., Metal Detectable No, Material of Construction Buna N, 1/8 in Thickness, -30 Degrees to 250 Degrees Temp. Range (F), Color Black, Standards ASME B16.21, ASTM D2000 BF 607